As she said, horses pick up on whatever is in your mind. Back up a bit and jump smaller jumps to build up YOUR confidence. You horse's confidence is built on yours.
Then you might have to play mind games with yourself. As you approach a jump, PRETEND that you are uber confident. Jump it the way you think your favorite jump rider would jump it. Strangely enough, this pretending will help make you feel more comfortable. It can make a huge difference.
I rode on a team that had a sports psychologist work with us. This is what we practised....visualization. I can't tell you how much difference it can make.
BTW, it's verticals I hate!! Oxers are so much easier, IMO. They almost ride themselves. Verticals take so much more care.
I hate Trak fences - hate them with a passion! The flippin' ditch always gets me....tisk tisk.
Any Stadium Fence makes me sweat - they are so unnatural looking and so uninviting to my eyes.
I just got off the phone with my Coach and she was telling me just as you were saying Allison - it is mind over matter and I have to start changing how I think. If I already failed in my mind, I've failed before I tried.
My two cents as a person who has had issues with oxers as well, my two main problems have been:
1. You guessed it, catching them in the mouth because I'm not talented at jumping, and get thrown off balance.
2. LACK OF CONFIDENCE...if you're scared of that oxer, your horse knows it. You need to build up slow and you need to really convince that horse that you WANT to go over it. Make sure you aren't looking down and make sure you don't have an ounce of hesitation in your body(or mind)
....I'm still working on that second one! Haha good luck!